Immunohistochemical analysis of initial and recurrent tumours of a representative case that was treated with TMZ is shown in Fig. 3A, a-d For all cases, the expressions of MLH1 and PMS2 were significantly decreased in the recurrent specimens (19.7 ± 14.8; 45.3 ± 27.2%) in comparison to their respective initial tumours (46.9 ± 19.1; 88.0 ± 7.4%) (p < 0.01, paired t-test) (Fig. 3B). The gene discussed is PMS2; the disease is neoplasm.